For surveillance purpose video cameras are often mounted on pan and/or tilt and/or zoom units, so called domes, in order to direct the video camera on the interesting scenes. Usually the user controls by means of a keyboard the direction at which the video camera is picking-up. However the domes can also be set-up to sequentially direct the video camera towards a number of predefined positions. At each position the video camera is waiting for a period of time before moving to the next position. In the following the word position is used for each setting including the direction of the video camera and the position of the zoom—in other words: the orientation and the size of the fields of view. After setting-up the dome and entering predefined positions the video camera moves from position to position automatically.
The video signal generated by the video camera is usually supplied to a digital video recording device and/or a picture monitor. The pictures which are seen either directly or in case of previously recorded video signals as playback include the pictures picked-up by the video camera in a sequence from position to position. Between the pictures from the positions blurred pictures are to be seen which are picked-up by the moving video camera. For instance such system is known from WO 95/35627.
One object of the invention is to improve the observation of scenes picked-up by the video camera and/or to improve automatically analysing the video signals.